Route parameters

So far we've seen how to link a static URL to a Blazor component. Static URLs are only useful for static content, if we want the same component to render different views based on information in the URL (such as a customer ID) then we need to use route parameters.

A route parameter is defined in the URL by wrapping its name in a pair of { braces } when adding a component's @page declaration.

@page "/customer/{CustomerId}"

Capturing a parameter value

Capturing the value of a parameter is as simple as adding a property with the same name and decorating it with a [Parameter] attribute.

@page "/"
@page "/customer/{CustomerId}"

<h1>
  Customer:
  @if (string.IsNullOrEmpty(CustomerId))
  {
    @:None
  }
  else
  {
    @CustomerId
  }
</h1>
<h3>Select a customer</h3>
<ul>
  <li><a href="/customer/Microsoft">Microsoft</a></li>
  <li><a href="/customer/Google">Google</a></li>
  <li><a href="/customer/IBM">IBM</a></li>
</ul>

@code {
  [Parameter]
  public string? CustomerId { get; set; }
}

All route parameters are captured as strings by default. The [Parameter] property must be of type string or a nullable string such as string? unless a route constraint is applied (see Constraining route parameters). Route matching is also case-insensitive; /customer/Microsoft and /customer/microsoft resolve to the same component.

Blazor also supports catch-all route parameters using the {*VariableName} syntax. A catch-all parameter captures the remainder of the URL path, including forward slashes. For example, @page "/blog/{*slug}" would match /blog/2026/07/hello-world and set the slug parameter to 2026/07/hello-world.

Note that when a navigation is made to a new URL that resolves to the same component type as the current page in an interactive render mode, the component will not be destroyed before navigation and the OnInitialized* lifecycle methods will not be executed. The navigation is simply seen as a change to the component's parameters. In Static Server Rendering (Static SSR) mode, however, each navigation is a full HTTP request that destroys and recreates the component, so OnInitialized* runs on every request.